Customer costs still uncertain for new water supply

By the end of the month, the San Diego Water Authority may decide whether to take water from the sea, and deliver it to the desert.

On Nov. 29, the authority’s board will vote whether to approve a contract for desalinated water from Poseidon Resources’ long-awaited plant in Carlsbad.

The plant promises to supply up to 10 percent of water needs for the drought-prone San Diego region, helping assure a small but stable local water supply.

“It’s a significant enhancement to our supply reliability,” said Ken Weinberg, water resources director for the authority.

But it comes at a price: water from the plant would cost nearly three times the amount charged by Metropolitan Water District, which provides about half the region’s water.

Under the proposed contract, the authority would buy 48,000 to 56,0000 acre-feet per year at $1,876 to $2,097 per acre-foot — the volume of water that covers an acre to a depth of one foot. By comparison, water from Metropolitan costs about $700 per acre-foot, Weinberg said.

And although the price of buying that water from Poseidon is contractually fixed, the expense to the 24 local water districts that make up the authority is still uncertain.

A survey of San Diego water districts found that the extra cost for desalinated water is likely to add $4.36 and $6.84 to the typical $75 monthly residential water bill.

Those numbers are estimates, though; some districts say their costs could be much higher. Otay Water District, for example, expects its ratepayers to see a 12 percent to 20 percent increase in their water bills if desalination comes online, general manager Mark Watton said.

That difference depends on how the authority accounts for the desalinated supplies within its rate structure, which includes varied prices for treated and untreated water. If it values desalinated water largely in terms of extra supply, it could spread the cost more widely among its 24 member districts. If it places greater value on the treatment of the highly purified, potable water from the desalination plant, that could add unwanted expense to districts such as Otay, which buy treated water from the authority.

To Vallecitos Water District, which is considering buying extra desalinated water to boost its local supply, the new source may be a welcome addition to Colorado River water and Metropolitan deliveries.

“The choices are east, which we’re already doing, north, which is Metropolitan, or west, which is desal,” said Vallecitos General Manager Dennis Lamb.

The final cost of desalination to ratepayers won’t be known until the water authority completes a study next year to sort out price variables.

This month, however, the authority faces a deadline: if the board doesn’t approve the contract by Nov. 29, Poseidon’s lease on the property expires, and the deal dissolves, said Sandy Kerl, deputy general manager of the authority.

At a Thursday board meeting of the authority, local water officials and members of the public weighed in on whether the agency would get what it pays for with desalination.

From hard-hat-clad ironworkers, to contractors, several speakers urged the authority to approve the desalination plant, which Poseidon estimates will add 2,000 jobs during construction of the nearly billion-dollar project, and employ 400 people during its operation. Jamul resident Victor Esparza urged the board to double the size of the desalination plant, to secure more local water.

But Julia Chunn-Heer, a representative for Surfrider Foundation, which has sued Poseidon over the marine impacts of its proposed plant, said San Diego should exhaust its options for conservation and water reclamation before turning to desalination.

“It doesn’t make sense to have this really expensive water that kills fish, just so people can have green lawns,” she said.

Weinberg said desalination would meet local needs, but said the board will decide at month’s end whether it is ready for a sea change in water supply.

“It’s local, it’s under our control in San Diego County, it’s below the earthquake line, it’s drought proof,” Weinberg said. “The question is, ‘Is this the right deal, is this the right time?’ ”